The invention relates to a process for manufacturing brush-type seals, for example, particularly brush-type metal seals. Furthermore, the invention relates to an arrangement for manufacturing such brush-type seals.
In the manufacture of brush-type seals, particularly those made of metal having inclined bristles, their inclination must be caused and the brushes must be densified or packed. In the manufacturing processes currently used in practice, this is achieved by means of two annealing processes. The first annealing process is used for placing the metal bristles in a sloped position; and the second process has the purpose of densifying the rounded brush which will then be ground at the inside diameter.
Thus a process for manufacturing a brush-type seal is known from European Patent Document EP 0 211 275 B1 whose bristles are fastened in a mounting preferably constructed as a holding ring. For this purpose, in a step A), a thread consisting of bristle material is first wound by way of two elongated spindles, which are spaced in parallel from one another, to form a dense thread stack which has an approximately oval cross-section. Then, in a step B), the thread seal is gripped on the two spindles by the fitting-on of clamping strips at the crowns. In a step C), the thread seal is severed by a cut in parallel to the spindles so that two mutually opposite, straight, semifinished brushes are created which are preferably equipped with bristles having the same length. Finally, in a step D), these semifinished brushes are bent to the desired brush contour, particularly to a circular arc contour, and are joined to form a closed ring.
For achieving an inclination of the bristles in their mounting, before process step B), the spindles which are wound with the thread seal are offset with respect to one another in the longitudinal direction. In this connection, when, for example, metal bristles are used, it is known to a person who is skilled in the art to carry out a recrystallization annealing for conserving the inclination of these metal bristles. This first annealing step before the severing of the thread seal for producing semifinished brushes is carried out as a function of the material, for example, at 720.degree. C.
After step D), if metal bristles are used in practice, a second annealing step is required for compacting the brushes produced so far and adjusting their axial dimensional accuracy.
This state of the art basically already requires high expenditures because two separate annealing steps must be carried out. In addition, particularly the resetting of the wound thread seal to an annealing device, which is required for the first annealing step, is complicated, cumbersome and requires high mechanical expenditures.
It is an object of the present invention to simplify the manufacturing process for brush-type metal seals.
This object is achieved by a manufacturing process for brush-type seals characterized by a) providing at least one ring-shaped brush-type seal having radially extending bristles of a length which, by way of the inclining of the bristles with respect to the radii of the ring-shaped brush-type seal leads at least essentially to the endeavored brush diameter; b) 1) positioning the at least one brush-type seal and at least one heatable annealing wall of an annealing device relative to one another so that the free bristle ends, while the bristles are bent, rest against the annealing wall; 2) rotating the at least one brush-type seal and at least the heatable annealing wall relative to one another until the bristles are inclined with respect to the radii of the ring-shaped brush-type seal in its ring plane by a definable angle; c) heating the annealing wall to a definable temperature; d) maintaining the temperature of the heated annealing wall for a definable time period; and e) removing of the at least one brush-type seal from the annealing device.
A brush-type seal having a brush is therefore produced first without any inclination of the wires or bristles in the future running direction with superimposed bristle shafts in a conventional manner machined to the finished size, in which case, however, no annealing treatments are carried out. During or after the mounting of the brush-type seal on a new type of annealing device, the endeavored radial setting is adjusted by a rotation to, for example, 45.degree.. Since the process according to the invention has the advantage that several brush-type seals can be treated simultaneously, as will be indicated later in connection with a preferred further development, for example, a spacer ring can now be mounted on the bristle stack of the already mounted or adjusted brush-type seal.
According to the above-mentioned further development, the mounting of another 2 to 20 brush-type seals, for example, can now take place according to the previous process steps. Finally, a clamping lid will be mounted which holds the stacked brush-type seals together.
By means of the bristles of the bristle-type seals inclined in the endeavored manner, the recrystallization annealing is now carried out, for example, at 780.degree. C. for 60 minutes, before the brush-type seals are removed from the annealing device after the cooling of the annealing device.
With the aid of the new annealing process, the inclination of the bristles and of the inside diameters of the brush can be established in one operation. This completely eliminates the two annealing processes carried out in the state of the art during the prefabrication, as well as the high-expenditure annealing devices required for this purpose. The processes are replaced by a new type of annealing process of the otherwise finished brush-type seal. The separate grinding of the inside diameter of the brush-type seal is also no longer absolutely necessary.
In the case of the process according to the invention for manufacturing brush-type seals with inclined bristles, it is also preferably provided that step b)2) is carried out simultaneously with step b)1). This minimizes the set-up time of the at least one brush-type seal with correctly inclined bristles in the annealing device. In addition, the combined rotational adjustment results in a particularly effective and no-disturbance setting up of the brush-type seal with correctly inclined bristles in the annealing device.
However, as an alternative to the above-mentioned further development, particularly as a function of the annealing wall, it can also be provided that step b)2) is carried out after the positioning of the at least one brush-type seal and of the heatable annealing wall of the annealing device relative to one another was completely concluded in step b)1).
Preferred inclinations of the bristles of the brush-type seal are such that, in step b)2, the bristles are inclined with respect to the radii of the ring-shaped brush-type seal in their plane by an angle of between approximately 15.degree. to approximately 75.degree., particularly between approximately 30.degree. to approximately 60.degree., and preferably approximately 45.degree..
As a function of the material of the bristles, such as the metal bristles, it is preferred for the heatable annealing wall to be heated up in step c) to a temperature of between approximately 500.degree. C. and approximately 1,000.degree. C., particularly between approximately 700.degree. C. and approximately 800.degree. C., and preferably between approximately 720.degree. C. and approximately 780.degree. C., and/or for the temperature of the head annealing wall reached in step c) to be maintained in step d) for a time period of approximately 30 min. to approximately 90 min., particularly approximately 45 min. to approximately 75 min. and preferably approximately 60 min.
According to another further development of the invention, a plurality of brush-type metal seals, for example, are aligned with one another and are simultaneously machined jointly. This possibility has been mentioned above. In particular, the new annealing process can be carried out for up to then, twenty, but also more brushes simultaneously on one arrangement. For this purpose, it is provided according to the invention that, before step c) of the heating of the annealing wall, a plurality of brush-type seals provided according to step a) and the heatable annealing wall of the annealing device according to step b)1) are positioned relative to one another and according to step b)2) simultaneously or subsequently, these brush-type seals and at least the heatable annealing wall are rotated relative to one another until the bristles are inclined by a definable angle with respect to the radii of the ring-shaped brush-type seal in its ring plane.
Another solution of the objective on which the invention is based consists of a manufacturing arrangement for ring-shaped brush-type seals, such as brush-type metal seals.
By means of the new annealing arrangement, the inclination of the bristles and of the inside diameters of the brush can be produced in one operation. In comparison with respect to the state of the art, this eliminates an annealing process as well as the high-expenditure annealing device required for this purpose. The separate grinding of the inside diameter of the brush-type seal is also no longer absolutely necessary.
According to a preferred further development of the arrangement according to the invention, the heatable annealing wall is the exterior wall of an annealing arbor onto which the at least one ring-shaped brush-type seal can be fitted. This embodiment is particularly adapted to the treatment of brush-type seals having inwardly directed bristles and is therefore advantageously suited for it.
In a preferred further development of the above-mentioned embodiment of the invention, it is provided that the annealing arbor is essentially cylindrical and, in its free end area designed for fitting on the at least one ring-shaped brush-type seal and situated opposite its mounting end in the annealing device, has a conical expansion cone. The outside diameter of this expansion cone increases from the free end of the annealing arbor in the direction of its mounting end in the annealing device, the maximal outside diameter of the annealing arbor corresponding at least essentially to the inside diameter of the ring-shaped brush-type seal with the inclined bristles which is to be completed. This further development of the annealing arbor advantageously, on the one hand, facilitates the placing of the brush-type seal on the annealing arbor and, on the other hand, the inclining of its bristles.
The handling of the brush-type seal, in particular during the fitting on the annealing arbor, is particularly simple and secure if the annealing device contains a holding device for mounting the at least one brush-type seal.
This can advantageously be further developed such that the holding device, for receiving a plurality of axially mutually aligned brush-type seals, contains spacer parts, such as spacer rings, which can be inserted between the latter and which ensure a secure and exact holding of the individual brush-type seals as well as an inclining of their bristles.
In order to be able to carry out the adjusting of the at least one brush-type seal and of the heatable annealing wall of the annealing device in a precise manner, it is preferred for the annealing device to contain, in particular, controllable driving devices which are designed for the adjusting of the at least one brush-type seal and of the heatable annealing wall of the annealing device relative to one another in order to position the at least one brush-type seal and the heatable annealing wall of the annealing device relative to one another and/or in order to rotate the at least one brush-type seal and at least the heatable annealing wall relative to one another until the bristles are inclined with respect to the radii of the ring-shaped brush-type seal in their plane by a definable angle. A further development thereof provides that the driving devices are designed, in particular, for adjusting the heatable annealing wall as well as preferably for an adjustment with a constant advance and/or a constant rotational speed.
In order to be able to bring the heatable annealing wall of the annealing device to a desired temperature, preferably, in particular, controllable heating devices are provided by which at least the heatable annealing wall of the annealing device can be heated to a temperature between approximately 500.degree. C. and approximately 1,000.degree. C., particularly between approximately 700.degree. C. and approximately 800.degree. C., and preferably between approximately 720.degree. C. and approximately 780.degree. C.
The arrangement will then represent a particularly precise and simple handling and machining of the at least one brush-type seal if the annealing device contains a control which controls the heating of the heatable annealing wall and the maintaining of the desired temperature in this case for a time period of approximately 30 minutes to approximately 90 minutes, particularly approximately 45 minutes to approximately 75 minutes and preferably approximately 60 minutes. The control preferably also controls a cooling operation of the heatable annealing wall of the annealing device.
In order to be able to possibly remove undesirable deformations or excessive lengths of the annealed bristles, it is advantageous to provide finishing devices for the finishing of the functional diameter of the brush of the at least one brush-type seal after the annealing treatment, which takes place corresponding to another further development of the invention.
If, in another embodiment of the arrangement, a protection against torsion is used, which holds the at least one brush-type seal relative to the annealing device in its position with inclined bristles, it is ensured that no automatic adjusting of the brush-type seal takes place during the annealing operation. In this case, the torsion protection device can, on one side, be applied to the annealing device or the at least one brush-type seal or optionally particularly to the holding device and, on the other side, to the at least one brush-type seal or to the annealing device.
Additional advantageous and preferred embodiments of the invention are described herein.
For illustrating embodiments, the invention will be described in detail in the following with reference to the drawing.